Head-Controlled Keyboard And Mouse For Disabled, using AVR and ATMega32 microcontroller

Easy Input is a head-controlled keyboard and mouse input device for paralyzed users. The system is built based on AVR ATMega32. It uses user’s head movement to control mouse movement on the monitor and user’s eye blinking to activate mouse click. Two main sensor used for this project are Freescale MMA6560Q accelerometers to detect head tilt and photodiode to detect user’s eye blinking.

Sensor outputs are sent to microcontroller ATmega32 via A/D converter. After processed by MCU, the data is transmitted remotely using wireless protocol. On the other side, a wireless receiver collects all the correct information through id filtering and then sends signals to a ground microcontroller through USART for interpretation process. After interpreted, mouse or keyboard instructions are sent to the computer via PS/2-to-USB cable.

The system has two operation modes: mouse mode and keyboard mode. When it is in mouse mode, the X and Y movements are directly mapped to the movement of mouse. The more your head tilts, the faster the mouse moves. When the user blinks, the mouse clicks. To distinguish between the unintentional blink and intentional blink, the program has to receive 10 consecutive blink packets from the transmitter to actually send a mouse click signal to the computer.